One way of looking at firmware is that it is fossilized software. One way of looking at hardware is that it is fossilized firmware. When you fossilize software you lose some of it's flexibility it becomes a static thing where the dynamics are set by bios settings or drivers that have to be loaded at run-time.
A HDL Language or Hardware Definition Language is meant to translate software directly into hardware. I am not sure you could achieve the dynamism of a hardware/firmware/Software system with just an HDL language. To redesign even a fraction of the systems to the same HDL language OS would be a major undertaking because there are so many platforms out there, on which to place an OS.
Why do you want to take on all the platforms at once?
A HDL can only update hw if it is a flexible architecture that responds to HDL.
I understand your frustration, but Hardware is often more than just logic, and so an HDL is useless for adding anything but logical changes.
Furthermore phones are integrated so deeply that Hardware changes require new designs. The difference is similar to the difference between a Modular circuit, as is found in a desk top unit, and a non-modular circuit, that is found in a laptop.
Until phones modularize so you can replace individual component boards, a trend that is moving in the opposite direction as they try to integrate more and more into a smaller footprint you will have to replace your phone every time there is a new HW upgrade.